Biotechnology Lecture Notes

Advantages and Disadvantages of Animal Cell Culture (Short Lecture Notes)

animal cell culture advantages and limitations

Advantages and Disadvantages of Cell / Tissue Culture

Tissue culture is an aseptic in vitro culture of animal or plant cells in a precisely controlled environmental condition. The term “Tissue Culture” was for the first time coined by Thomas Burrows. Even though the in vitro culture of prokaryotes and both plant and animal cells are possible now, the term ‘Tissue Culture’ generally denotes to Animal Cell / Tissue culture. The term ‘Plant Tissue Culture’ symbolizes the in vitro culture of plant cells.

In cell culture the cells are maintained in an artificial environment consists of a suitable culture vessel containing a culture medium. The medium supplies all the nutrients, growth factors, and required gases for the growth of the cells. Moreover, the physiochemical environment of the culture system is strictly monitored most probably through automated systems. The control of the physiochemical environment in the culture system is one of the most important advantages of cell culture system. However, the tissue culture process is not always profitable and there are a plenty of difficulties in maintaining the cells in in vitro conditions. The present post describes the Advantages and Disadvantages of animal cell or tissue culture techniques.

Advantages of Animal Cell Culture:

Ø  Physio-chemical environment in the culture such as pH, temperature, osmolarity and level of dissolved gases can be precisely controlled in the in vitro system.

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Biotechnology Lecture Notes

Applications of Restriction Endonuclease Enzymes in Biotechnology (Short Notes)

Restriction enzymes in Genetic Engineering

Applications of Restriction Enzymes
(The Significance / Importance and Uses of Restriction Endonucleases in Biotechnology)

Restriction endonucleases (also called as molecular scissors) are a class of nuclease enzymes which cut the DNA strand at precise locations. They are specific endonuclease enzymes in the cells which first recognize the specific sequence (called restriction sites) within the DNA strand and cleave the phosphodiester backbone of the DNA at specific sites. The Nobel Prize in 1978 (in Physiology and Medicine) was shared by Werner Arbor, Daniel Nathans and Hamilton Smith for the discovery of restriction enzymes and their applications in molecular genetics. Restriction enzymes are now an inevitable tool for the manipulation of DNA in various recombination studies both in vitro and in vivo. The main applications of restriction enzymes are:

(1). Construction of Restriction Maps

(2). Construction of DNA Fingerprints

(3). Recombinant DNA Technology (rDNA Technology)

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Biotechnology Lecture Notes

Batch Fermentation vs Continuous Fermentation Process: Similarities and Differences – A Comparison Table

Difference continuous and batch fermentation

Batch Fermentation vs Continuous Fermentation Process
(Similarities and difference between Batch Fermentation and Continuous Fermentation Process)

Batch Fermentation and Continuous Fermentation are the two commonly adopted Industrial Fermentation methods for the scale production of microbial biomass or metabolites.

Batch Fermentation: Here the fermenter is first filled with the raw material (carbon source). Then the microbes are added and allowed to ferment the raw material under optimum pH and aeration. The products remain in the fermenter until the completion of fermentation. After fermentation, the products are extracted and the fermenter is cleaned and sterilized before next round. Thus here the fermentation is done as separate batches.

Continuous Fermentation: Here the exponential growth rate of the microbes is maintained in the fermenter for prolonged periods of time in by the addition of fresh media are regular intervals. The metabolite or the product of fermentation is extracted for the overflow from the fermenter. Thus unlike batch fermentation, in continuous fermentation, the fermentation process never stops in between and it continues to run for a long period of time with the addition of nutrients and harvesting the metabolites at regular intervals.

The present post describes the Similarities and Differences between Batch Fermentation and Continuous Fermentation Process as a Comparison Table.

Similarities between Batch Culture and Continuous Culture Fermentation Methods

Ø  Both are industrial fermentation methods for the large scale production.

Ø  Both methods can be used for the production of microbial biomass or products.

Ø  Both run under controlled environmental conditions

Ø  The mechanical components of fermenter is almost similar in both types

Difference between Batch Fermentation and Continuous Fermentation Process

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Biotechnology Lecture Notes

Industrial Fermentation Process (Batch, Fed-batch and Continuous Fermentation)

types of fermentation process

Fermentation Technology
(Types of Industrial Fermentation Processes)

Fermentation: An art from the past, a skill for the future…
Brain McNeil

What is fermentation?

Ø  Fermentation is a metabolic process which converts carbohydrates to alcohols, organic acids or gases by the activity of enzymes of microbial origin.

Ø   Microbes involved in fermentation process: Bacteria and Fungi.

Ø  The process of anaerobic respiration in the muscle cells of animals during exercise which produce lactic acid is also a type of fermentation.

Ø  The technique of fermentation was very ancient in origin.

Ø  Egyptians and Sumerians had the knowledge of the technique of converting starchy grains to alcoholics.

Ø  For a microbiologist, the word ‘fermentation’ means many processes such as:

$   A method of mass cultivation of microbes under aerobic or anaerobic conditions.

$   Any biological process occurs in the absence of oxygen.

$   Spoilage of food by microbial activity.

$   Production of alcoholic beverages, organic acids, antibiotics or biopolymers

$   Partial oxidation of carbohydrates

What is industrial fermentation?

Ø  The intentional use of fermentation technology for the large scale production of microbial biomass or metabolites is called industrial fermentation.

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Molecular Biology Tutorials

DNA Repair Mechanism – Part I Introduction (DNA Damaging Agents, DNA Damages and Recovery of DNA Damages)

Introduction to DNA Repair Mechanisms

“Genetic variation is important for evolution, but the survival of the individuals
demand genetic stability”

What is DNA repair?

DNA is the genetic information carrier molecule in the cell and thus it is very essential to keep the genetic information intact. Even though DNA holds a prime position, it is one of the highly susceptible molecules in the cells because DNA can be damaged by a number of factors both internal and external in origin. It is very surprising to know that, our cells lose approximately 5000 nucleotides every day due to different damages of the DNA. If these damages are not rectified properly, our cells will be subjected to severe mutations and that will be fatal for the survival of the individual cells and the organism itself. DNA replication process in the cell which ensures the production of exact copy of the genetic information is very accurate due to the high fidelity of DNA polymerase enzyme. However, the process of DNA replication is not 100 percent error free. DNA polymerase enzyme sometimes accidentally introduces wrong bases which will disrupt the normal Watson-Crick base paring of the DNA. There are also many possibilities of DNA damage during genetic recombination happens during gametogenesis by meiotic cell division. If the damages or errors in the DNA are not corrected in the somatic cells, it may leads to the development of cancer or it results in the loss of function of genes. More than that, if DNA damages occur in the gametes is not rectified, it will be carried over to next generation through progenies. Thus, damage to the genetic materials is a major threat to all organisms. In order to counteract these threats, cells has evolved many methods to overcome and rectify different types DNA damages. All these methods are collectively termed as DNA REPAIR mechanisms. Similar to DNA replication, transcription and translation, the process of DNA repair is also a prime molecular event in the cells which is very essential for the ultimate survival of the cells and also for the survival of the organism.

DNA Repair and Nobel Prize in Chemistry (2015)

DNA Repair Mechanism

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